There is no such thing as a small side effect of antihypertensive drugs, every antihypertensive drug has side effects, and different patients have different reactions to the drugs. Clinical antihypertensive drugs are divided into five categories, each drug has different side effects, such as calcium antagonists can appear lower extremity edema, angiotensin converting enzyme inhibitors can appear dry cough, angiotensin II receptor antagonists can lead to nausea, diuretics can lead to electrolyte disorders, beta-blockers can appear bradycardia and so on. Each antihypertensive drugs may have some adverse reactions and side effects, there is no absolutely perfect antihypertensive drugs, different patients may have different reactions when taking drugs, so it is impossible to assess which antihypertensive drugs have the least side effects, under the guidance of the physician to choose the most appropriate drug for the patient.